Luteinizing Hormone Receptor Protein Research Articles

P-636 Effects of maternal circadian rhythm changes: intergenerational influences on testicular steroidogenesis in offspring

Abstract Study question Do alterations in the maternal circadian rhythm during pregnancy and lactation result in changes to the male offspring’s testicular steroidogenesis intergenerationally? Summary answer The expression of proteins associated with steroidogenesis is altered due to maternal circadian rhythm changes during pregnancy and lactation periods. What is known already Circadian rhythms impact diverse physiological processes, including reproduction. Several clock genes have been linked to reproductive function. However, there is a complex interaction between hormones, fertility, and the circadian clock. It has been shown that disruption of the circadian clock machinery has negative effects on reproductive biology. Current literature indicates a potential relationship between the circadian clock, testicular steroidogenic-related gene expression profiles, and testosterone synthesis. Steroidogenesis involves a complex cascade of enzymatic reactions. An increasing body of evidence from animal studies suggests a relationship between maternal chronodisruption and long-term offspring health and fertility. Study design, size, duration Male offspring from pregnant Wistar rats (n = 60) were exposed to control (12 hours light/12 hours dark), short day (SD) (8 hours light/16 hours dark), or long day (LD) periods (16 hours light/8 hours dark) during only pregnancy, only lactation, or both periods (n = 6/group) categorized as control, SD pregnancy (SD-P), SD lactation (SD-L), SD pregnancy and lactation (SD-P+L), LD pregnancy (LD-P), LD lactation (LD-L), LD pregnancy and lactation (LD-P+L) groups. Participants/materials, setting, methods The expression of critical components of testicular steroidogenesis, including steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (cytochrome p450scc), 17-beta hydroxysteroid dehydrogenase 3 (HSD17B3), androgen receptor (AR), and luteinizing hormone receptor (LHR), was analyzed in the testis by counting the percentage of positively-stained Leydig cells and ImageJ analysis of immunohistochemistry and western blot. Serum FSH, LH, and testosterone hormones were measured at four zeitgeber time (ZT) points (ZT0, ZT6, ZT12, and ZT18) using ELISA. Main results and the role of chance All of these testicular steroidogenic enzymes were localized in the Leydig cell, and AR was predominantly observed in the Sertoli cell. Although there are no significant differences between the groups in terms of immunolocalization patterns, the expressions of p450scc and AR proteins were significantly decreased in the SD-P and SD-L groups compared to the control group (p < 0.001). In addition, western blot data indicated a decreased expression of p450scc in the SD-P+L group. However, an increased expression of HSD17B3 was detected in both SD-P+L and LD-P+L groups compared to the control group (p = 0.003, p < 0.001, respectively). Among the steroidogenesis-related proteins evaluated, the protein expression levels of StAR and LHR proteins were not altered. FSH showed a statistically significant increase in the LD-L (ZT0), SD-P+L (ZT12), LD-L (ZT12), and LD-P+L (ZT18) groups when compared to the corresponding control groups at the respective time points (p < 0.05). In contrast, LH levels decreased significantly in the LD-P+L (ZT0) group (p < 0.05). Nevertheless, no statistical difference was determined for testosterone levels between groups. Limitations, reasons for caution Most studies on circadian rhythm have used rodent models. Results from animal models are often informative. However, there is a limitation in the appropriate translation of findings in rodents to human studies. Wider implications of the findings The effects triggered by maternal chronodisruption can be intergenerationally transmitted, potentially affecting offspring health. Our results indicate alterations in the expression of proteins involved in testicular steroidogenesis and time-point-dependent changes in the FSH and LH hormone levels due to maternal circadian rhythm changes, further supporting the potential implications for offspring. Trial registration number This work was supported by research grants from the Scientific and Technological Research Council of Turkey (TUBITAK) (SBAG 219S636) and Akdeniz University, The Scientific Research Projects Coordination Unit (TYL-2018-3580).

Differential expression of FSHR and LHR genes and proteins during development of rabbit ovarian follicles.

The development of an ovarian follicle is a complex process at the cellular and molecular level that is mainly regulated by follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR). To elucidate the contribution of these receptors to ovarian follicle development, it is necessary to determine their expression profiles during this biological process. Therefore, this study aimed to investigate the relationship between ovarian development pattern and the differential ovarian expression pattern of FSHR and LHR genes as well as proteins at different developmental stages. Ovaries were collected from 30 New Zealand rabbits at day 0 (birth), week 2 (neonate), week 4 (cub), week 16 (maturity), and day 18 pregnancy. Ovarian histology, and gene as well as protein expression were determined using light microscopy, real-time PCR and western blotting, respectively. The results showed that the expression levels of FSHR mRNA and protein increased coincidently with age and the growth of ovarian follicles. The levels of LHR mRNA and protein remained low from the day of birth until week 4 and became significantly higher by week 16 coinciding with appearance of growing and antral follicles, which have a defined thecal layer. FSHR gene and protein expression decreased with pregnancy, whereas LHR increased, reaching a peak level during pregnancy. It can be concluded that changes in FSHR and LHR gene and protein expression could be related to the growth and development of follicles, indicating the regulatory role for these receptors in rabbit folliculogenesis.

Cellular Heterogeneity of the Luteinizing Hormone Receptor and Its Significance for Cyclic GMP Signaling in Mouse Preovulatory Follicles.

Meiotic arrest and resumption in mammalian oocytes are regulated by 2 opposing signaling proteins in the cells of the surrounding follicle: the guanylyl cyclase natriuretic peptide receptor 2 (NPR2), and the luteinizing hormone receptor (LHR). NPR2 maintains a meiosis-inhibitory level of cyclic guanosine 5'-monophosphate (cGMP) until LHR signaling causes dephosphorylation of NPR2, reducing NPR2 activity, lowering cGMP to a level that releases meiotic arrest. However, the signaling pathway between LHR activation and NPR2 dephosphorylation remains incompletely understood, due in part to imprecise information about the cellular localization of these 2 proteins. To investigate their localization, we generated mouse lines in which hemagglutinin epitope tags were added to the endogenous LHR and NPR2 proteins, and used immunofluorescence and immunogold microscopy to localize these proteins with high resolution. The results showed that the LHR protein is absent from the cumulus cells and inner mural granulosa cells, and is present in only 13% to 48% of the outer mural granulosa cells. In contrast, NPR2 is present throughout the follicle, and is more concentrated in the cumulus cells. Less than 20% of the NPR2 is in the same cells that express the LHR. These results suggest that to account for the LH-induced inactivation of NPR2, LHR-expressing cells send a signal that inactivates NPR2 in neighboring cells that do not express the LHR. An inhibitor of gap junction permeability attenuates the LH-induced cGMP decrease in the outer mural granulosa cells, consistent with this mechanism contributing to how NPR2 is inactivated in cells that do not express the LHR.

Effect of electroacupuncture at different acupoints on follicle development and related factors in serum and ovary tissues of PCOS rats

To observe the effect of electroacupuncture (EA) at different acupoints on follicle development, expression of gonadotropins and their receptors and anti-Müllerian hormone(AMH), inhibin B(INHB) in polycystic ovarian syndrome (PCOS) rats, so as to explore its mechanisms underlying improvement of PCOS. Sixty female SD rats were randomized into six groups: control, model, Zusanli(ST36), Sanyinjiao(SP6), Guanyuan(CV4) and combination (ST36+SP6+CV4, n=10 rats/group). The PCOS model was established by gavage of Letrozole solution (1.0 mg/kg) once daily for 21 consecutive days. Rats of the control group were given 1% Carboxymethyl Cellulose (CMC, 1 mg/kg). EA (2 Hz) was applied to ST36, SP6, or/and CV4 for 20 min, once daily for 14 consecutive days. The number of follicles was counted, and the ovarian structure and follicular development were observed under light microscope after H.E. stain, and the contents of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), AMH, and INHB were assayed by enzyme-linked immunosorbent assay, and the ratio of LH/FSH was calcula-ted. The immunoactivity of LH receptor (LHR) and FSH receptor (FSHR) proteins was detected by immunohistochemistry. After modeling, the number of follicles at the growth stage, contents of serum LH, AMH and INHB, and ratio of LH/FSH were significantly increased, and serum FSH level and FSHR, LHR immunoactivity were remarkably decreased in the model group relevant to the control group (P<0.05, P<0.01). Following EA intervention, the number of follicles at the growth stage in the SP6, CV4 and combination groups, LH/FSH ratio and serum AMH levels in the 4 EA groups, INHB contents in the ST36, CV4 and combination groups were significantly reduced (P<0.05, P<0.01), while serum FSH contents in the 4 EA groups, FSHR immunoactivity at the early stage in the ST36 group and LHR immunoactivity at both early and late stages in the ST36 and CV4 groups were considerably increased in comparison with those of the model group (P<0.01, P<0.05). The therapeutic effect of SP6 was significantly superior to that of CV4 in down-regulating serum LH level (P<0.01), but significantly inferior to that of CV4 in up-regulating serum FSH content and in down-regulating LH/FSH ratio and serum AMH and INHB levels (P<0.05, P<0.01). The effect of CV4 was comparable to that of ST36 in up-regulating serum FSH, and in down-regulating serum LH/FSH ratio, AMH and INHB levels (P>0.05). EA of CV4, SP6, ST36 and ST36+CV4+SP6 can reduce the number of follicles at the growth stage and regulate the expression levels of gonadotropins in PCOS rats. The effects of EA of CV4 and ST36 are evidently better than those of EA of SP6 in up-regulating serum FSH content and in down-regulating LH/FSH ratio, and serum AMH and INHB levels, and EA of SP6 is evidently superior to EA of CV4 down-regulating LH level, but without synergistic effect among the 3 acupoints.

Estrogenic properties of genistein acting on FSHR and LHR in rats with PCOS.

The purpose of the study was to study the activity of the phytoestrogen genistein (GEN) act- ing on FSHR and LHR in rat ovaries with polycystic ovary syndrome (PCOS). Sixty rats were di- vided into six groups. Rats in the dose group received genistein at a concentration of either 5 (low genistein dose group, L-gen), 10 (middle genistein dose group, M-Gen) or 20 (high genistein dose group, H-Gen) mg per kg of body weight per day. Estrogen group (EG, received 0.5 mg/kg Dieth- ylstilbestrol). Concentration of sex hormones in serum was quantified by enzyme-linked immuno- sorbent assay (ELISA). Expressions of follicle-stimulating hormone receptor (FSHR) and lutein- izing hormone receptor (LHR) protein were determined by immunohistochemistry. Treatment with genistein resulted in a strong stimulation of the concentration of sex hormone in serum. The concentration of progesterone and FSH was significantly higher in H-Gen when compared to the PCOS model control group (MG) (P ⟨ 0.01). In contrast, the concentration of testosterone, LH and the ratio of LH/FSH decreased in GEN treatment groups compared to MG, the effect was statistically significant, tested by the ANOVA test (p⟨0.01). For hormone receptor activity, treat- ment with genistein resulted in an improvement of ovarian function with LHR protein expression being enhanced and FSHR protein expression being suppressed. Our results demonstrate that Genistein played a significant role in regulating FSH and LH receptor expression to improve perimenopausal ovarian and uterine function.

Prolactin modulates luteal activity in the short-nosed fruit bat, Cynopterus sphinx during delayed embryonic development

The aim of this study was to evaluate the role of prolactin as a modulator of luteal steroidogenesis during the period of delayed embryonic development in Cynopterus sphinx. A marked decline in circulating prolactin levels was noted during the months of November through December coinciding with the period of decreased serum progesterone and delayed embryonic development. The seasonal changes in serum prolactin levels correlated positively with circulating progesterone (P) level, but inversely with circulating melatonin level during first pregnancy showing delayed development in Cynopterus sphinx. The results also showed decreased expression of prolactin receptor-short form (PRL-RS) both in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. Bats treated in vivo with prolactin during the period of delayed development showed significant increase in serum progesterone and estradiol levels together with significant increase in the expression of PRL-RS, luteinizing hormone receptor (LH-R), steroidogenic acute receptor protein (STAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) in the ovary. Prolactin stimulated ovarian angiogenesis (vascular endothelial growth factor) and cell survival (B-cell lymphoma 2) in vivo. Significant increases in ovarian progesterone production and the expression of prolactin-receptor, LH-R, STAR and 3β-HSD proteins were noted following the exposure of LH or prolactin in vitro during the delayed period. In conclusion, short-day associated increased melatonin level may be responsible for decreased prolactin release during November–December. The decline in prolactin level might play a role in suppressing P and estradiol-17β (E2) estradiol levels thereby causing delayed embryonic development in C. sphinx.

GnRH-agonist implants suppress reproductive function and affects ovarian LHR and FSHR expression in prepubertal female cats

Effect of a GnRH-agonist (deslorelin) was studied on reproductive function and ovarian luteinizing hormone receptor (LHR) and follicle stimulating hormone receptor (FSHR) expression in prepubertal female cats that were either implanted with 4.7-mg deslorelin (implanted: n = 6) or not (controls: n = 18) or ovariohysterectomized at prepubertal age (prepubertal OVH: n = 6). Body weights, fecal estradiol, and sexual behavior of implanted and control cats were monitored for 48 weeks followed by collection of ovaries and uteri. Ovaries and uteri were collected from control cats at follicular, luteal, and inactive stage (n = 6/group) and from prepubertal OVH cats at prepubertal age. Ovaries and uteri were analyzed for anatomical/histological characteristics. Ovaries were also analyzed for LHR and FSHR expression. Statistical analysis showed higher (P ≤ 0.05) body weight in control than implanted cats only during 22nd to 26th weeks of the study. Estrus was observed in control cats only. Deslorelin reduced (P ≤ 0.05) ovarian weight and number of antral follicles but did not affect endometrial thickness and gland diameter. However, myometrial thickness of implanted cats was significantly lower than control cats at follicular and luteal stage. Ovarian LHR mRNA expression was lower (P ≤ 0.05) in implanted cats than control cats at follicular stage. FSHR mRNA and LHR protein expression did not differ among the three groups. FSHR protein expression was lower (P ≤ 0.05) in prepubertal OVH cats and was not affected by deslorelin. In conclusion, deslorelin suppresses reproductive function in prepubertal female cats for at least 48 weeks possibly through a change in the ovarian mRNA expression of LHR.

Repeated use of mifepristone and levonorgestrel and their effect on the ovarian function in mice.

To investigate the effects of repeated mifepristone and levonorgestrel use on estrous cycle and expression of ovarian follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in mice. Ovarian FSHR and LHR mRNA expression was measured using real-time quantitative reverse transcription-polymerase chain reaction, while the protein levels were measured using immunohistochemistry. Repeated use of mifepristone and levonorgestrel significantly lengthened the estrous cycle and decreased FSHR and LHR mRNA and protein expression in the ovaries of mice at 4, 24, and 48 days after discontinuing drug use. Repeated use of mifepristone and levonorgestrel had significant main effects on estrous cycle length and the mRNA expression and protein level of ovarian FSHR and LHR. Repeated mifepristone and levonorgestrel use and withdrawal time had a significant interaction with mouse estrous cycle (F = 16.65, P < 0.05), ovarian LHR and FSHR mRNA expression (F = 563.072, P < 0.05), and protein level (F = 6.536, P < 0.05). Repeated use of mifepristone and levonorgestrel can lead to sustained damage to ovarian function through inhibition of ovarian FSHR and LHR expression in mice.

Triptorelin and cetrorelix induce immune responses and affect uterine development and expressions of genes and proteins of ESR1, LHR, and FSHR of mice

Context: GnRH immunity can reduce the expression of pituitary GnRH levels, and cause the changes in reproductive behaviors. It is unclear whether triptorelin (TRI) and cetrorelix (CET) immunity influences uterine development and expression of follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), and estradiol receptor 1 (ERS1) in the uterus.Objective: The study investigated the effects of active immunity of GnRH agonist and antagonist on uterine development, microstructures, expression of hormone receptors mRNAs, and proteins in uteri.Materials and methods: One hundred and five mice were assigned into CET, TRI, and control groups (CG). Mice in CET-1, CET-2, and CET-3 (n = 15) were subcutaneously injected with 10, 20, and 40 μg CET antigens for seven days, respectively. Mice in TRI-1, TRI-2, and TRI-3 were injected with 10, 20, and 40 μg TRI antigens for seven days, respectively. The qPCR and Western blot were implemented to determine expressions of ESR1, LHR and FSHR mRNAs, and proteins.Results: Compared with CG, the uterine weights of CET-1, CET-2, and CET-3 increased by 42.86, 62.86, and 10.00% on day 35 (p < 0.05), respectively. Uterine weights of TRI-2, TRI-3 reduced by 28.57% and 11.43% (p < 0.05), respectively. The uterine cavity in CET-1, CET-2, and CET-3 increased; the uterine wall became thick. The cytoplasm of endometrial epithelial cells (EEC) increased slightly. In TRI group, the uterine wall thinned. Uterine cavity became narrow slightly in TRI-1. Numbers of uterine glands reduced. The endometrium epithelial thickness (EET) in CET-1 and CET-2 increased by 68.21% and 79.46% (p < 0.05), respectively. EET in TRI-1 was decreased by 13.69%. Uterine wall thicknesses (UWT) in CET-1 and CET-2 were higher than CG, with the increment of 28.59% and 30.72%. UWT of TRI-1, TRI-2, and TRI-3 reduced by 29.35, 15.36, and 14.41%, respectively. Expressions of ESR1, FSHR, and LHR mRNAs in CET and TRI mice increased. ESR1 and FSHR protein levels increased in all experimental mice (p < 0.05), with a maximum of TRI-3. LHR protein levels of the CET decreased. LHR protein levels of TRI group increased, with a maximum of TRI-3 (p < 0.05). ESR1 protein level had significant negative correlations to mRNA expressions of ESR1, LHR, and FSHR.Conclusions: CET immunity promoted the uterine development, improved EET and UWT, and also promoted the expressions of ESR1 and FSHR protein levels. It lessened the LHR protein levels. TRI immunity blocked EET and UWT, inhibited uterine growth and development. The efficacy of CET immunity was more obvious than TRI.

Equine chorionic gonadotropin influence on sheep oocyte in vitro maturation, apoptosis, and follicle-stimulating hormone receptor and luteinizing hormone receptor expression.

We assessed the effects of equine chorionic gonadotropin (eCG) on oocyte in vitro maturation (IVM), apoptosis, and follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), and gonadotropin-releasing hormone receptor (GnRHR) expression and mRNA levels. Cumulus-oocyte complexes (COCs) were recovered from sheep ovaries and pooled in groups, before being cultured in IVM media containing varying eCG concentrations. Maturation and apoptosis rates were then calculated. Expression of FSHR, LHR, and GnRHR mRNA in oocytes was measured using quantitative reverse transcription polymerase chain reaction. Protein levels were ascertained by western blotting. Matured oocytes displayed and released an intact first polar body. Sheep oocyte maturation rates gradually increased as eCG concentration was raised from 0 to 20 µg/mL. Apoptosis rates of eCG-treated oocytes were lower than those of the control group, and were lowest using 20 µg/mL eCG. FSHR, LHR, and GnRHR mRNA expression increased (P < 0.01, P < 0.05, and P < 0.05, respectively, compared to 0 µg/mL eCG) with eCG concentration, being highest following exposure to 20 µg/mL. FSHR and GnRHR protein levels were significantly higher in oocytes administered 20 µg/mL eCG compared with those matured in the absence of eCG. eCG dose positively correlated with FSHR, LHR, and GnRHR mRNA and protein expression. In conclusion, eCG enhances maturation and decreases apoptosis of oocytes undergoing IVM, and heightens FSHR, LHR, and GnRHR expression. Such increased expression may facilitate oocyte IVM. These findings contribute to our understanding of the mechanisms of underlying hormonal control of sheep oocyte IVM, advancing ovine reproductive methods.

GnRH-agonist implantation of prepubertal male cats affects their reproductive performance and testicular LH receptor and FSH receptor expression

This study was conducted to investigate the effect of GnRH-agonist implantation in prepubertal tomcats on sexual behavior, reproductive performance, and expression of testicular LH receptor (LHR) and FSH receptor (FSHR) and also to compare the testicular characteristics, LHR and FSHR expression between prepubertal and adult tomcats. In experiment 1, 3-month-old tomcats (n = 6/group) were either treated with or left without 4.7 mg deslorelin implants. Semen collection and evaluation were performed just before castration at 48 weeks after treatment; removed testes were analyzed for mRNA and protein expression of LHR and FSHR. We were able to collect semen from six non-treated cats, whereas in treated cats, semen was uncollectable. The results revealed that sexual behavior was absent in the implanted cats throughout the study period. Testicular volume was found to decrease from 30 weeks after treatment onward in the implanted cats compared to the controls (P < 0.05). Semen production was found only in non-implanted cats. Testicular tissue score, seminiferous tubule diameter, and LHR protein expression were found lower in the implanted cats (P < 0.05), but no differences were observed in mRNA expression of LHR and protein expression of FSHR between groups. The mRNA expression of FSHR was higher in the implanted (P < 0.05) compared to control cats. In experiment 2, testes from prepubertal (n = 6) and adult (n = 6) male cats were collected after castration and analyzed for mRNA and protein expression of LHR and FSHR. No differences were observed in the protein expression of LHR and FSHR between the two groups, whereas mRNA expression of FSHR was higher in prepubertal cats (P < 0.05). Testicular and epididymal weight, diameter of seminiferous tubules, and the testicular grade were higher in the adult compared to prepubertal cats (P < 0.05). In conclusion, deslorelin implants suppressed protein expression of LHR and enhanced mRNA expression of FSHR along with suppression of reproductive function without any adverse effects for at least 48 weeks in male cats.

Cetrorelix and Triptorelin active immunization influences follicle development and receptor expressions of ovaries in mice

The study investigated comparatively the effects of active immunization of Cetrorelix and Triptorelin on the follicle development, histological structures, and expressions of FSHR and LHR proteins in the ovary. One hundred and five female mice, 35 days old, and body weight of 26.56±2.89g, were randomly assigned into Cetrorelix (CET), Triptorelin (TRI) and control groups (CG). Mice in CET-1, CET-2 and CET-3 (n=15) were subcutaneously injected with 0.1, 0.2 and 0.4mL Cetrorelix antigen (100μg/mL) for seven days, respectively. Mice in TRI-1, TRI-2 and TRI-3 were injected with 0.1, 0.2 and 0.4mL Triptorelin antigen (100μg/mL) for seven days. Mice in CG (n=15) were injected with 0.2mL saline for seven days. Western blotting was utilized to determine the expressions of follicle stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) proteins. ELISA was used to measure the serum FSH and LH concentrations. The ovarian slices were observed under optical microscopy. The results showed that the ovarian weights of CET and TRI groups increased slightly with a maximum increment of 27.02% of CET-1 mice on day 35. Ovarian weights in TRI group increased dose-dependently with a maximum increment of 45.77% in TRI-3 on day 35. The numbers of the primordial follicle (POF), primary follicle (PF), secondary follicle (SF) and mature follicle (MF) of CET and TRI groups increased at different degrees when compared to CG. The granular layer in SF was arranged tightly and zona pellucida (ZP) was thickened. Follicles developed fully. Follicle longitudinal diameter (FLD), follicle transverse diameter (FTD) and follicle wall thickness (FWT) in CET and TRI groups increased as compared to CG. FLD, FTD and FWT of TRI-3 had a larger increment than CG and CET-1 on days 21 and 35. Expression levels of FSHR and LHR proteins in TRI group increased when compared to CG. Expression levels of FSHR and LHR proteins of CET group decreased. Serum FSH of TRI group was slightly higher than the CG and CET group on day 21. On day 35, serum FSH levels of CET-1 and TRI-1 were greater than CG and the rest of the subgroups. Serum FSH levels had no significant differences among all groups. Expression levels of LHR and FSHR proteins in CET group had obvious negative correlations to FLD, FTD and FWT. However, in the TRI group, these correlations were positive. In conclusion, Cetrorelix and Triptorelin immunization could improve ovarian growth, increase the follicle numbers, enhance dose-dependently the FLD, FTD and FWT, and eventually promote the ovary and follicle development. Cetrorelix decreased expression levels of FSHR and LHR proteins in the ovaries of mice. Triptorelin enhanced expression levels of FSHR and LHR proteins. Triptorelin treatment had more obvious effects than Cetrorelix treatment.

TNF-α Suppressed FSH-Induced LH Receptor Expression Through Transcriptional Regulation in Rat Granulosa Cells.

Several inflammatory cytokines regulate ovarian function. TNF-α is produced in granulosa cells under physiological conditions and has a reciprocal action on follicle development. In contrast, in pelvic inflammatory diseases, TNF-α is excessively produced in the pelvic cavity and has an adverse effect on reproductive functions. The objective of this study was to elucidate the mechanism of action of TNF-α on the expression of LH receptor (LHR) in immature rat granulosa cells. TNF-α suppressed FSH-induced LHR mRNA and protein expression and was not associated with cAMP accumulation. By using a luciferase assay, the construct containing base pairs -1389 to -1 of the rat Lhcgr promoter revealed that TNF-α decreased FSH-induced promoter activity. In response to TNF-α, nuclear factor (NF)-κB p65 was translocated to the nucleus, and the suppressive effect of TNF-α on LHR mRNA expression was abrogated by an NF-κB inhibitor. In a chromatin immunoprecipitation assay, TNF-α induced the association of NF-κB p65 with the rat Lhcgr transcriptional promoter region. NF-κB p65 and histone deacetylase (HDAC) interact to mediate expression of several genes at a transcriptional level. HDAC activity is thought to induce tight connections within local chromatin structures and repress gene transcription. Furthermore, the TNF-α-induced suppression of LHR mRNA expression was blocked by an HDAC inhibitor. Taken together, these results suggest that the interaction of NF-κB p65 with HDAC in the promoter region of rat Lhcgr might be responsible for TNF-α action on the regulation of LHR.

Age-associated changes in granulosa cell transcript abundance in equine preovulatory follicles.

Age-related changes in follicle paracrine signalling are not defined, and follicular gene transcript abundance could predict oocyte viability. Granulosa cells from preovulatory follicles of mares considered Young (n=12; 4-14 years), Mid-aged (n=9; 15-19 years) and Old (n=14; 20-27 years) were evaluated for transcript abundance related to systemic and follicle-specific pathways. Gene transcript abundance for receptors of insulin, adiponectin and peroxisome proliferating factor-γ were higher or tended to be higher in Mid-aged or Old than Young mares. Transcript abundance for interleukin (IL)-6 was elevated in Old versus Young mares, and IL-6 signal transducer was elevated in Old versus younger groups. Expression of tumour necrosis factor (TNF) receptor superfamily member 1A was higher in Mid-aged than Young mares, whereas TNF-inducible gene 6 protein mRNA tended to decrease in Mid-aged versus Young and Old mares. Genes for LH receptor and steroidogenic acute regulatory protein tended to be increased in Old versus Mid-aged and Young mares, respectively. Young and Old mares had higher mRNA for tissue-type plasminogen activator than Mid-aged mares. Thioredoxin-2 mRNA was higher in Old than younger groups. We observed age-related changes in mRNA of receptors for metabolic hormones, inflammatory processes, steroidogenic hormones, tissue remodelling and mitochondrial function, which could contribute to and/or mark alterations in follicular function and fertility.

Effects of luteinizing hormone receptor signaling in prostate cancer cells.

The importance of androgen signaling in prostate cancer (PC) is well described and prostate cancer cells retain the ability to directly synthesize androgens. Luteinizing hormone (LH) can induce expression of steroidogenic enzymes and trigger androgen production, but the regulation of this process is not well-described. Here, we explored the impact of silencing LH receptor (LHR) silencing on androgen synthesis and on several relevant signaling pathways in PC. LHR mRNA and protein expression was evaluated in LNCaP PC cells treated with LHR-siRNA. MTS assay was used to measure the effect of LHR-siRNA on proliferation in LNCaP and 22RV1 PC cells. Treated LNCaP and LAPC-3 cells were also assayed for differences in androgen synthesis and expression of steroidogenic enzymes, PSA, AR, and critical signaling molecules including PKA, ERK1/2, PI3K, AKT2, and HER2. We confirmed that functional LHR is expressed in both androgen-sensitive and castrate-resistant PC specimens. Treatment with LHR-siRNA effectively silenced LHR gene and protein expression and prevented LH-mediated proliferation and androgen synthesis in prostate cancer cells. LHR silencing also downregulated expression of AR, PSA, PKA, ERK1/2, PI3K, AKT2, and HER2. Collectively, these data demonstrate that silencing LHR expression suppresses androgen synthesis and signaling and the LH-LHR pathway may represent a viable therapeutic strategy in PC.

NHE8’s role in male fertility involves LHR protein trafficking (1097.8)

We reported last year that NHE8, the newest member of the sodium/hydrogen exchanger family, plays an important role in male fertility. NHE8 has abundant expression in the male reproductive organs, particularly in Leydig cells and epididymal duct cells. Male mice lacking NHE8 are infertile. Loss of NHE8 expression also resulted in reduced luteinizing hormone receptor (LHR) expression in male mice. Furthermore, luteinizing hormone (LH)‐stimulated cAMP production was reduced in isolated NHE8KO Leydig cells. After NHE8 expression was silenced by NHE8 siRNA in Leydig cells, reduced LHR expression and dramatically reduced cAMP production after LH stimulation were noted. Confocal microscopic imaging showed that LHR protein was targeted to early endosome in Leydig cells in the absence of NHE8 function instead of the plasma membrane. Therefore, male infertility in NHE8KO mice is due to the disruption of LHR protein trafficking, which results in an interruption in the precise hormone regulation that governs normal sperm development. This study is supported by NIH grant R01DK073638.Grant Funding Source: Supported by NIH grant R01DK073638

LH, Progesterone, and TSH can Stimulate Aldosterone In Vitro: A Study on Normal Adrenal Cortex and Aldosterone Producing Adenoma

Endocrine factors different from ACTH or angiotensin II can stimulate aldosterone secretion and have a role in the pathophysiology of hyperaldosteronism. Aldosterone may increase in luteotropic/progestogenic and in hypothyroid states; LH and, occasionally, TSH receptors have been detected in normal adrenal cortex and aldosterone-producing adenoma. The aim of the study was to compare adrenal contents of LH and TSH receptors between normal cortex and aldosterone-producing adenoma and to evaluate the ability of LH, its product progesterone, and TSH to stimulate aldosterone secretion in vitro from primary adrenocortical cells. Surgical aldosterone-producing adenoma fragments from 19 patients and adrenal cortex fragments from 10 kidney donors were used for Western blotting and cell cultures. LH (n=26), TSH (n=19) and progesterone (n=8) receptor proteins were investigated; LH receptor-mRNA was also tested in 8 samples. Aldosterone responses in vitro to LH, progesterone, and TSH stimulation were assayed. LH and TSH receptors were more expressed in adenoma than normal cortex (p<0.01, p<0.05, respectively); progesterone receptor was observed in 6/8 samples. Aldosterone increased after in vitro stimulation with LH (5/12 adenoma, 1/7 normal cells), progesterone (4/5 adenoma, 5/6 normal cells), and TSH (3/5 adenoma and 3/5 normal cells). LH and TSH receptors were more expressed in aldosterone producing adenoma than normal adrenal cortex. LH, progesterone, and TSH can stimulate aldosterone in vitro. Similar mechanisms could participate in vivo in the aldosterone increase in lutheotropic, progestogenic, or hypothyroid states and may exist in both normal adrenal cortex and adenoma in responsive individuals.

The toxicity mechanism of sodium fluoride on fertility in female rats

Recognition of the harmful effects of sodium fluoride (NaF) on human reproduction is increasing, especially as it relates to female reproduction. However, the mechanism by which NaF interferes with female reproduction is unclear. The aims of the present study were to investigate the effects of fluoride exposure on female fertility and to elucidate the mechanisms underlying these effects. Female Sprague–Dawley rats were divided into three groups: one control group and two NaF-treated groups (100 and 200mg/L in the drinking water for 12weeks). Several parameters were evaluated, including: (i) fluoride concentrations; (ii) estrogen (E2) and progesterone (P) concentrations; (iii) estrogen receptor alpha protein (ERα); (iv) progesterone receptor (PgR) protein; (v) follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) protein. The results indicated that administration of NaF lead to significant decreases in E2 and P levels in the serum and in the expression of FSHR protein. In addition, fluoride exposure significantly increased Erα and PgR protein expression levels and LHR protein expression. These results suggest that the reproductive hormone reduction and the abnormalities of related receptor proteins expression are important factors underlying the decreased fertility observed in female rats that have been exposed to NaF.

Alarelin active immunization influences expression levels of GnRHR, FSHR and LHR proteins in the ovary and enhances follicular development in ewes

We investigated the effects of gonadotropin releasing hormone (GnRH) agonist on expressions of GnRH receptor (GnRHR), follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) proteins in the ovaries and follicular development in the ewes. Forty-two pre-pubertal ewes were assigned to experimental groups 1 to 5 (EG-I to EG-V) and control group (CG). Ewes in EG-I, EG-II and EG-III were subcutaneously injected with 200, 300 or 400 μg alarelin antigens twice (on days 0 and 14), respectively. Ewes in EG-IV and EG-V were subcutaneously injected with 200 μg and 300 μg alarelin antigen four times (on days 0, 7, 14 and 21). Ewes in CG were subcutaneously injected with a solvent twice (on days 0 and 14). Serum concentrations of GnRH antibody in the EGs increased and were higher than (P<0.05) that of CG from day 14 to day 60. GnRH antibody concentrations in EG-IV and EG-V were higher than that in EG-I, EG-II and EG-III from days 35 to 45. Expressions of GnRHR protein in EG-IV and EG-V were lower than that in CG (P<0. 01). Expressions of FSHR and LHR proteins in EGs increased. Levels of FSHR and LHR proteins in EG-IV and EG-V (P<0.05) were higher than CG. Ovarian weights in EGs increased. Values of follicle vertical diameter, follicle transverse diameter, follicle wall thickness, follicle externatheca thickness and follicle internatheca thickness in EG-III and EG-V were greater than other groups. Primordial follicles and primary follicles developed quickly in alarelin-immunized animals. Secondary follicles and mature follicles became more abundant. Mitochondria, mitochondrial cristaes and cortical granules increased. Serum FSH concentrations of EGs remained higher than that in CG from days 28 to 70 (P<0.05). Alarelin immunization stimulated GnRH antibody production, suppressed expression of GnRHR protein, enhanced expressions of FSHR and LHR proteins in ovaries, promoted FSH secretion and thereby accelerated the development of ovaries and follicles in ewes.

English

Bone morphogenetic proteins (BMPs), belonging to the transforming growth factor-beta family, are crucial factors in follicular growth and development in the mammalian ovary. In this study, we examined the effects of BMP2, 4, 6 and 7 on goat granulosa cells by in vitro culture. The results showed that BMP2, 4 and 7 increased follicle-stimulating hormone receptor (FSHR) level in goat granulosa cells whereas they decreased luteinizing hormone receptor (LHR) level in both transcript and protein levels; however, BMP6 upregulated LHR transcript and protein level in goat granulosa cells, whereas it had no effect on FSHR level. FSHR knockdown increased granulosa cell apoptosis. Our data provided the i¬rst evidence that BMP2, 4, 6 and 7 may inhibit granulosa cell apoptosis through the regulation of FSHR and/or LHR level. These i¬ndings provided new insight into the biological functions of BMP2, 4, 6 and 7 for follicular development in goat ovary. Key words: Granulosa cell, bone morphogenetic proteins (BMPs), follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR)